Subject: [PATCH AUTOSEL 5.10 32/44] net: dsa: mv88e6xxx: Fix mv88e6352_serdes_get_stats error path

From: Sasha Levin <[email-masked]>
Date: Tue, 16 Jan 2024 15:00:01 -0500

From: Tobias Waldekranz <[email-masked]>

[ Upstream commit fc82a08ae795ee6b73fb6b50785f7be248bec7b5 ]

mv88e6xxx_get_stats, which collects stats from various sources,
expects all callees to return the number of stats read. If an error
occurs, 0 should be returned.

Prevent future mishaps of this kind by updating the return type to
reflect this contract.

Reviewed-by: Vladimir Oltean <[email-masked]>
Reviewed-by: Florian Fainelli <[email-masked]>
Signed-off-by: Tobias Waldekranz <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/dsa/mv88e6xxx/chip.h   | 4 ++--
 drivers/net/dsa/mv88e6xxx/serdes.c | 8 ++++----
 drivers/net/dsa/mv88e6xxx/serdes.h | 8 ++++----
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index 51a7ff44478e..67e52c481504 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -536,8 +536,8 @@ struct mv88e6xxx_ops {
 	int (*serdes_get_sset_count)(struct mv88e6xxx_chip *chip, int port);
 	int (*serdes_get_strings)(struct mv88e6xxx_chip *chip,  int port,
 				  uint8_t *data);
-	int (*serdes_get_stats)(struct mv88e6xxx_chip *chip,  int port,
-				uint64_t *data);
+	size_t (*serdes_get_stats)(struct mv88e6xxx_chip *chip, int port,
+				   uint64_t *data);
 
 	/* SERDES registers for ethtool */
 	int (*serdes_get_regs_len)(struct mv88e6xxx_chip *chip,  int port);
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.c b/drivers/net/dsa/mv88e6xxx/serdes.c
index 6920e62c864d..9494d75eec62 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.c
+++ b/drivers/net/dsa/mv88e6xxx/serdes.c
@@ -314,8 +314,8 @@ static uint64_t mv88e6352_serdes_get_stat(struct mv88e6xxx_chip *chip,
 	return val;
 }
 
-int mv88e6352_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
-			       uint64_t *data)
+size_t mv88e6352_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
+				  uint64_t *data)
 {
 	struct mv88e6xxx_port *mv88e6xxx_port = &chip->ports[port];
 	struct mv88e6352_serdes_hw_stat *stat;
@@ -631,8 +631,8 @@ static uint64_t mv88e6390_serdes_get_stat(struct mv88e6xxx_chip *chip, int lane,
 	return reg[0] | ((u64)reg[1] << 16) | ((u64)reg[2] << 32);
 }
 
-int mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
-			       uint64_t *data)
+size_t mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
+				  uint64_t *data)
 {
 	struct mv88e6390_serdes_hw_stat *stat;
 	int lane;
diff --git a/drivers/net/dsa/mv88e6xxx/serdes.h b/drivers/net/dsa/mv88e6xxx/serdes.h
index 14315f26228a..035688659b50 100644
--- a/drivers/net/dsa/mv88e6xxx/serdes.h
+++ b/drivers/net/dsa/mv88e6xxx/serdes.h
@@ -116,13 +116,13 @@ irqreturn_t mv88e6390_serdes_irq_status(struct mv88e6xxx_chip *chip, int port,
 int mv88e6352_serdes_get_sset_count(struct mv88e6xxx_chip *chip, int port);
 int mv88e6352_serdes_get_strings(struct mv88e6xxx_chip *chip,
 				 int port, uint8_t *data);
-int mv88e6352_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
-			       uint64_t *data);
+size_t mv88e6352_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
+				  uint64_t *data);
 int mv88e6390_serdes_get_sset_count(struct mv88e6xxx_chip *chip, int port);
 int mv88e6390_serdes_get_strings(struct mv88e6xxx_chip *chip,
 				 int port, uint8_t *data);
-int mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
-			       uint64_t *data);
+size_t mv88e6390_serdes_get_stats(struct mv88e6xxx_chip *chip, int port,
+				  uint64_t *data);
 
 int mv88e6352_serdes_get_regs_len(struct mv88e6xxx_chip *chip, int port);
 void mv88e6352_serdes_get_regs(struct mv88e6xxx_chip *chip, int port, void *_p);
-- 
2.43.0